Environmental protection measures increasingly necessitate the avoidance of organic solvents in chemical formulations. Aqueous systems are accordingly being used more and more.
Aqueous dispersions of organopolysiloxanes are known per se. For example, the preparation of aqueous silicone dispersions based on hydroxylated diorganopolysiloxane, colloidal silicon dioxide and an organic amine or sodium hydroxide is described in U.S. Pat. No. 4,221,688 (R. D. Johnson, Dow Corning Corporation; published on 9th Sept. 1980).
Aqueous silicone dispersions which are obtained by addition of an alkali metal silicate to an anionically stabilized aqueous emulsion of polydiorganosiloxane having hydroxyl end groups are known from U.S. Pat. No. 4,244,849 (J.C. Saam, Dow Corning Corporation; published on 13th Jan. 1981). Aqueous dispersions which contain siliconate in addition to the polydiorganosiloxanes having hydroxyl groups in the terminal units and (organo)metallic compounds are described in U.S. Pat. No. 4,816,506 (N. Gamon, Wacker-Chemie GmbH; published on 28th Mar. 1989).
Therefore, it is an object of the present invention to provide aqueous organopolysiloxane dispersions which are stable and ready-to-use without a long storage time. A further object of the present invention is to provide aqueous organopolysiloxane dispersions which form elastomers having different mechanical properties in a relatively simple manner and within a short time.